February 26-28, 2019

Colorado Convention Center
Denver, CO

Scott WisherMidwest Regional ManagerCascade

As the Midwest Regional Manager for Cascade Technical Services, LLC, who acquired Vironex, Inc. in early 2015, an environmental remediation specialty company, Mr. Wisher manages a staff of environmental professionals and field technicians to successfully implement environmental solutions for the environmental consulting community.

Mr. Wisher has an extensive background in business management, P&L, in-situ chemical oxidation, in-situ chemical reduction, active and passive remediation, monitored natural attenuation, bioremediation, and advanced site characterization.Mr. Wisher is the technical lead for the Midwest Mountain Region while handling all aspects of profit and loss. Mr. Wisher leads the sales effort in the region while continuing to work extensively with his clients on high resolution site characterization (HRSC) using the only Denver-based membrane interface probe (MIP) and ultraviolet optical screening tool (UVOST), designing in situ remediation solutions, implementing our Search & Destroy® methodology, and managing Regional business operations.

PLATFORM PRESENTER - Getting Over It: Overcoming Site Challenges

In-Situ Fracturing Analysis Using the High Resolution Injection Tool for Design Optimization of Sodium Permanganate Injection

Background/Objectives.Because of the required direct and sustained contact between in-situ chemical oxidation reagents, such as sodium permanganate, and contaminants of concern, such as trichloroethene (TCE), injection below soil fracture pressure is critical to maximize contact and distribution. At a former manufacturing site with TCE-impacted groundwater in Little Rock, Arkansas, Weston Solutions, Inc. (Weston) utilized the Vironex High Resolution Injection Tool (HRIT) to evaluate injection pressures, and flowrates to optimize full-scale design parameters during a sodium permanganate injection. Weston utilized the HRIT to evaluate both direct push technology (DPT) and injection well (IW) locations in order to optimize flow rates without formation the fracturing.

Approach/Activities.The HRIT is a direct push and injection well based tool equipped with an integrated Hydracell positive displacement pump, digital flow meter, and uphole and downhole pressure transducers. At the site, these parameters were measured in real time as the HRIT injected design volumes of water at both IWs and DPT locations, each of which was surrounded by radially-placed monitoring points. These monitoring points were used to measure influence of groundwater with respect to thermal and hydraulic response to assess radius of influence, distribution, and maximum injection flow at pressures below fracture pressure. Specifically at each location, pressure was slowly increased to illicit a water flow response. In order for sodium permanganate to be considered at full scale, the desired response was that injection flow would be roughly linear to injection pressure such that large changes in pressure, e.g. fracturing, followed by flow would not occur. Additionally, if fracturing was measured, at what pressure did it occur. HRIT flows and pressures were measured at multiple intervals in DPT locations, and across a 10 foot screen in the IW locations.

Results/Lessons Learned.HRIT analysis indicated that water, as analogous to sodium permanganate in tems of viscosity, could be injected at both DPT and IWs without fracturing the formation and introducing the reagent through uncontrolled fracture flow. Generally, flow in both IWs and DPT locations was linear to pressure as flow was increased. Specifically, at IW locations, HRIT measured that flow could be maintained at approximately 7 gallons per minute (gpm) at below 30 pounds per square inch (PSI). At DPT locations, HRIT measured that injection could be maintained at approximately 9 GPM at less than 50 PSI. Both pressure measurements in IWs and DPT points were below fracture pressure as evidenced by no rapid reduction in pressure that would result from fractured formation conditions. Weston utilized these data to design the full scale event, taking into account the measured ROI during HRIT testing, pressures measured, and achievable flow rates. Full scale implementation is scheduled to begin in October 2015, and multiple sampling events will be completed prior to Battelle 2016. Weston will present these HRIT data along with pre- and post-injection analytical data. Weston believes that the understanding of subsurface distribution through a fracturing analysis has provided significant valuable information for a successful full-scale design. These data, coupled with traditional data such as permanganate oxidant demand, seepage velocity, and radius of influence, provide the required set of pre-injection design data to maximize the likelihood of success.